Yes the only way I could see this working is if they had the entire area mapped out in a 3d grid and multiple cameras at different angles feeding the bot data on the location of the people inside the grid. The robot would then use the info from the grid to plan a path that would constantly change. Though i cant see that being very practical.

Yeah, I see the problem with that. I guess it would use multiple cameras on it to create a knowledge of everyone within, lets say, 15 feet. Then it would just navigate through that and do the 'constantly change route' thing.